Electrostatic air cleaners use electric energy to generate electrostatic forces which create air flow without the use of a fan or other moving parts. Electrostatic forces also enable the air cleaner to collect airborne contaminants such as dust, smoke, oil mist, pollen, pet dander and other small debris particles from the air circulated in dwellings, workplaces, and other structures. Generally, known electrostatic air cleaners utilize two arrays of electrodes excited by high-voltage. In a known design, the first electrode array comprises wire or rod-shaped electrodes (hereinafter “wire electrodes”), while the second electrode array comprises plate electrodes. A high-voltage generator creates an electrical charge between the first and second electrode arrays.
The particulate matter enters the region of the first electrode array and is charged before entering the region of the second electrode array, where it is removed from the air stream. Specifically, due to the high-voltage charge at the wire electrodes, free electrons are stripped off of atoms and molecules in the surrounding air. These electrons migrate to the positively charged wire electrodes, where they are collected. The removal of free electrons leaves the stripped atoms and molecules positively charged, which are repelled from the positively charged wire electrodes and attracted to the negatively charged plate electrodes. The addition of the electrons from the negatively charged plate electrodes also produces negative air ions that are propelled from the trailing edge of the plate electrodes. Thus, the ionic forces exerted on atoms and molecules create a silent movement of air through the air cleaner.
Because collected and adhered debris greatly reduces a wire electrode's efficiency and effectiveness, the debris must be periodically removed. In the past, the cleaning of the wire electrodes of the electrostatic air cleaners has been difficult because of the close spacing of the electrode arrays and the high voltages applied to the closely spaced, oppositely charged arrays. Care must be exercised to see that the electrode assemblies are cleaned effectively and are not electrically shorted together or to a ground. For this reason, some devices require periodic shut-down and disassembly so that the wire electrodes can be removed for washing. Other devices are rappers or shakers which strike or vibrate the wire electrode assemblies to loosen collected debris and cause it to fall from the electrode assemblies.
Another known method of cleaning the wire electrodes is to thread the wire electrode through a bead. The bead is dimensioned to remain in frictional contact with the wire electrode and remove debris as it travels the length of the electrode. To cause the bead to travel along the length of electrode, the air cleaner is rotated and gravity causes the bead to travel from an initial position along the electrode and frictionally remove contaminates from the outer surface of the electrode. The air cleaner is then returned to its original position and the bead returns to its initial position along the electrode. To maintain the efficiency of the air cleaner, the air cleaner may need to be rotated multiple times to further clean the electrode.
A disadvantage of this type of cleaning is that the air cleaner could be heavy and bulky, and it may be inconvenient for users to lift and rotate a heavy and bulky air cleaner. Furthermore, in the process of lifting and rotating the air cleaner, the user could drop the cleaner and cause damage to the device. Also, when a user lifts and rotates the air cleaner, the debris that is removed from the electrode is likely to contaminate the user.
It is therefore desirable to provide a cleaning mechanism for a wire electrode assembly that is convenient, easy to use and does not require the lifting or rotating of a heavy, bulky air cleaner apparatus.